the hilt is the part of the sword that shields the hand or is the transition part of the sword from blade to the handle. literally means to go all the way one can with the sword "take it to the hilt" ... but is used as a metaphor in all situations.

the hilt prevented his hand from being injured when his hand slipped off the handle.

the phrase that is yelled out when a man wants his lady friend to deepthroat him, not the mighty thrust of a broadsword where every inch of its deadly blade is stuffed into some poor sucker's belly stopping only when the righteous hilt is pressed against the flesh of the victim.

Jane, i want you to take it to the hilt tonight. TO THE HILT!! -with arm upraised in a commanding manner-